Search PubMed⌕ Search

Biomedical subjects

A Panà

Publications and source records attributed to A Panà.

At least 37 records · Page 2Linked to original sources
PubMed1990

Depuration of Mytilus galloprovincialis experimentally contaminated with hepatitis A virus.

Mussels (Mytilus galloprovincialis) were contaminated with known amounts of laboratory strains of hepatitis A virus and Poliovirus 1 and the effectiveness of a self-cleansing mechanism was studied using a pilot depuration system. Both viruses were rapidly bioaccumulated by mussels and the maximal concentration of about 10(4) TCID50/ml was reached within 1.5 hours. Depuration was carried out up to 24 h; infectivity titer decreased to 10(2) TCID50/ml and 10(3.2) TCID50/ml within 6 h in hepatitis A virus and Poliovirus 1 contaminated mussels, respectively, but only a very slight further decrease was obtained after 24 h. E. coli was used as a control; within 24 h the concentration decreased from 40 to 2 bacteria/ml of mussel (MPN). The elimination of bacteria is not a reliable parameter to control the effectiveness of viral depuration.

Animals↗
PubMed1990

Susceptibility of mammalian, avian, fish, and mosquito cell lines to rabies virus infection.

The relationship between plasma membrane receptor organization and cell susceptibility in vitro was investigated in mammalian, avian, fish, and arthropod cell lines infected with fixed rabies virus. IMR32, HeLa, CER, and EPC cells were widely susceptible to infection with CVS virus, whereas a lower level of specific viral antigens was detectable in A. albopictus cells. In spite of these differences, the amount of infectious virus particles bound to the various cell surfaces was similar. Competition experiments carried out with plasma membranes extracted from ability of these components to bind the virus and to prevent infection. The different cellular permissiveness to rabies infection described here did not correlate with significant differences in number or in chemical structure of the receptor binding sites, but more likely with events following virus adsorption.

Adsorption↗
PubMed1990

Identification of enteroviruses isolated from sea-water: indirect immunofluorescence (IIF).

In this research the Enteroviruses presence in sea water was studied. In previous studies presumptive Enteroviruses were revealed in 43% and in 77% of sea water samples analyzed. It was necessary to identify viral particles isolated from marine water because the detection of this kind of virus was performed only on the basis of cytopathic effect appearance on cell cultures. The aim of this research was to verify the suitability of Indirect Immunofluorescence for identification of presumptive Enteroviruses isolated from marine waters. 13 field strains from RC 37 cells (Cercopithecus Kidney cell line) were tested. Pools of Horse immune sera against COXS, POLIO and ECHO, and anti-horse antibodies conjugated with fluorescein were used. The results revealed the presence of Coxsackie virus and Echo virus. There were many problems related with ECHO identification for the presence of cross-reactions with COXS. The IIF method cannot be performed routinely, because it did not show high level of specificity and sensibility, and it is expensive. This methodology can be used only in particular cases and in laboratories with competent virologists and related facilities. In the future, the only suitable methodology for identification of Enteroviruses isolated from field samples is based on the use of RNA and DNA probes.

Antigens, Viral↗
PubMed1989

Hepatitis B virus infection in children in Sardinia, Italy.

Possible hepatitis B immunization of all newborns, regardless of the mother's HBsAg status, is a strategy under consideration for selected hyperendemic areas in Italy. Sardinia is one such area. However, in 1987 in Sardinia, the prevalence of hepatitis B markers in children under 11 years was estimated at 1.7% and the prevalence of hepatitis B surface antigen (HBsAg) at 0.2%. A much higher prevalence of HBsAg was recently observed among adults in this area: 8.7% among men and 5.2% among pregnant women. This contrasting pattern is unlikely to be due to bias: the sampling procedures adopted were appropriate and the percentage of refusals was very low (2.2%). The observed low hepatitis B marker prevalence in young age groups might be the result of a cohort effect due to the improved socio-economic conditions and changes in behaviour that have occurred in Sardinia over the last few years. The finding of only 3 HBsAg+ individuals out of 1,826 children tested, in spite of the 5.2% HBsAg prevalence among pregnant women in that region, is probably attributable to the low proportion of HBeAg positive individuals among the HBsAg+ carrier mothers in this area. At present, immunization of all newborns in Sardinia cannot be recommended.

Age Factors↗
PubMed1989

Effect of cellular function inhibitors on the infection of Frp/3 cells by hepatitis A virus.

The effect of some cellular function inhibitors on hepatitis A virus (HAV) adsorption and on the successive events of infection in a monkey cell line (Frp/3 cells) was investigated. Treatments of Frp/3 cells with colcemide, vinblastine and cytochalasin D, which affect cytoskeleton organization, indicated that neither microtubules nor microfilaments play an important role in the early events of HAV infection. Monensin, which acts as an ionophore on intracellular vesicle compartments inhibited HAV infection probably at the uncoating step. Inhibition of viral replication to a different degree was observed with both inhibitors of oxidative phosphorylation, such as dinitrophenol and sodium azide, and with an inhibitor of glycolysis, 2-deoxy-D-glucose. However, none of these compounds significantly affected the early steps of infection, thus demonstrating that HAV replication is largely dependent upon cell energy.

Azides↗
PubMed1989

Morphological changes in HAV-infected Frp/3 cells and immunolocalization of HAAg.

Electron and immunoelectron microscopic studies were carried out on HAV-infected Frp/3 cells. The infection led to a distinctive cytopathic effect (CPE) arising on day 3 up to the complete detachment of monolayers on day 7. Infected cells exhibited progressive modifications, beginning from the formation of long helical polyribosomes. Subsequently, hypertrophy, cisternal dilatation and degranulation of the RER could be observed. Furthermore, the formation of concentric membranous bodies (CMB), large myelin-like structures and annulate lamellae could be revealed at later times of infection. 24-27 nm virus-like particles were observed within cytoplasmic vesicles or outside extensively degenerated cells. Indirect immunoperoxidase staining were used to localize HAV antigen (HAAg) in thin sectioned infected Frp/3 cells. Vesicular inclusion bodies, often seen to contain electron-lucent particles, resulted darkly stained as well as tracts of the RER and myelin-like structures. Negatively stained preparations from cell lysates revealed small clusters of HAV particles which sometimes appeared to be still associated with residual membrane fragments. Our findings seem to suggest that HAV replication occurs in close association with cytoplasmic membranes and a direct involvement of the RER seems to be demonstrated.

Antigens, Viral↗
PubMed1989

Ultrafiltration: an efficient second step for hepatitis A virus and poliovirus concentration.

The efficiency of seeded hepatitis A virus and poliovirus recovery from 1 l of dechlorinated tap water or different buffer was evaluated using a molecular filtration system. All the experiments were performed using a polysulfonate membrane of 10,000 molecular weight limit. Under standard conditions hepatitis A virus recovery was 100% of the input, but the percentage was reduced dramatically when the inflow pressure was increased. In contrast, poliovirus recovery was low under standard conditions, but it improved when the membranes were pretreated with different buffers. The best recovery was obtained using beef extract at neutral pH.

Buffers↗
PubMed1989

Membrane lipid components interacting with hepatitis A virus.

The involvement of lipid components in hepatitis A virus (HAV) attachment to host cells has been investigated. Isolated Frp/3 cell membranes and whole lipids, phospholipid and glycolipid fractions extracted from them were able to bind the virus and to prevent infection. Treatment of virus with various phospholipids or glycolipids demonstrated the participation of phosphatidylserine, phosphatidylethanolamine and galactose in HAV binding. Results obtained added further information on the receptor specificity of host cells for HAV.

Animals↗
PubMed1989

Hepatitis A virus infection in children in Sardinia, Italy.

The prevalence of antibody to hepatitis A virus (anti-HAV) in a sample of 1662 Sardinian children aged 3 to 11 years was estimated by ELISA. The overall anti-HAV prevalence was 3.8 per cent; it increased from zero among children of 3 to 7.2 per cent in children of 11 years. A slight male predominance was observed (4 versus 3.6 per cent). Anti-HAV prevalence was inversely related to the number of years of education received by the father and positively related to the number of households in the sample. Children whose fathers had received less than six years of schooling, had a 6.2-fold risk (Cl 95 per cent = 2.6-15.3) and children with five or more households under one roof had a 2.6-fold risk (Cl 95 per cent = 1.4-5.0) of previous exposure to hepatitis A virus (HAV) infection. These findings suggest that exposure of Sardinian children to hepatitis A virus is relatively low, probably because of improvements in socioeconomic conditions in recent years in the island. However, overcrowding and poor education in the father of schooling appear to be important determinants of infection.

Child↗
PubMed1988

Cytomegalovirus infection in day care centers in Rome, Italy: viral excretion in children and occupational risk among workers.

From nine day care centers in Rome, Italy, 253 children of middle to low socioeconomic classes were examined for cytomegalovirus (CMV) excretion in saliva. The overall excretion rate was 13%, with no marked differences between centers. Socioeconomic level, age of enrollment, chronological age, length of attendance, and number of siblings did not have any discernible influence on viral shedding. The most notable result is that during the second year of age, 100% of the excretors had been breast fed, but only 60% in the third year, indicating that maternal transmission is the most likely source of children's infection early in life. Serologic survey of 82 female workers in day care centers, 82 matched housewives, and 229 female students aged 14 to 18 years who were in training to care for children showed that at 14 years of age the CMV seropositivity rate is 85, which suggests that primary infection during childbearing age is an uncommon event in Rome.

Adolescent↗
PubMed1988

Hepatitis B and Delta virus infection among heterosexuals, homosexuals and bisexual men.

The hepatitis B virus (HBV) and hepatitis Delta virus (HDV) infection rates were estimated in patients attending a venereal disease outpatient clinic: 759 heterosexuals and 154 homosexual-bisexual men. The anti-HBc prevalence was higher in homo-bisexual men (68.8 per 100) than in heterosexuals (41.8 per 100), whereas HBsAg was roughly the same in the two groups (about 6 per 100). The anti-HBc prevalence rate among heterosexuals was higher than that estimated in hospital personnel from the same geographical area. A positive association between anti-HBc prevalence and present or past sexually transmitted diseases (STD) was found among homo-bisexual men. Anti-HBc was also positively associated with herpes simplex type 2 antibodies in both heterosexuals and homo-bisexual men. These data are consistent with the hypothesis that sexual behavior also plays a role in the spread of infection among heterosexuals. Ten of the 46 HBsAg-positive subjects were anti-HDV positive: 6 of the 36 heterosexuals and 4 of the 10 homosexuals. All HDV-positive subjects had present or past STDs. These findings suggest sexual transmission of HDV infection.

Age Factors↗
PubMed1987

Immunity to tetanus among Italians born between 1956 and 1963.

Systematic mandatory immunization of children against tetanus begun in Italy in 1968. Preceding birth cohorts, accounting for almost 80% of present Italian population, were poorly immune or totally non-immune; around 90% of cases of tetanus occurring in Italy in recent years are observed among them. In a national sample of 4770 young males born between 1956 and 1963, about one third was not protected. Prevalence of non-immune subjects was greater in the Southern Regions and the Islands, in rural areas, among the unemployed, among the older birth cohorts.

Adolescent↗
PubMed1987

Study of the chemical nature of Frp/3 cell recognition units for hepatitis A virus.

Research has been carried out in order to clarify the chemical nature of cell receptors interacting with a fast growing strain of hepatitis A virus (HAV) producing a cytopathic effect on Frp/3 cells. Cell surface susceptibility to HAV attachment has been studied after treatment with enzymes acting on different chemical groupings. Results obtained showed a lowering of cell susceptibility to HAV infection following the action of phospholipase A2, phospholipase C, trypsin and beta-galactosidase. These data suggested that phospholipids, proteins and galactose participate to the cellular receptorial area for HAV.

Cell Line↗
PubMed1987

Detection of hepatitis A virus in the stools of healthy people from endemic areas.

One-hundred-ninety-two stool samples were tested for the presence of human Hepatitis A antigen. Sixteen of these were also evaluated for the presence of infectious virus. All samples were obtained from young and apparently healthy people from endemic areas for Hepatitis A disease. The isolation of the infectious virus from these stools demonstrates clearly the wide diffusion of the virus in these areas, and its transmission by the oral-fecal route.

Adolescent↗
PubMed1987

The effect of lipophilic amines on the growth of hepatitis A virus in Frp/3 cells.

The effect of lipophilic amines on hepatitis A virus infection in a monkey cell line (Frp/3 cells) was studied. Ammonium chloride, amantadine, methylamine and dansylcadaverine inhibited viral antigen synthesis when added to the cells at least one hour after the attachment step. Results obtained suggest that the HAV entry pathway in Frp/3 cells follows an endocytic route and that viral uncoating takes probably place in endosomes and/or lysosomes.

Amantadine↗
PubMed1987

Indirect immunofluorescence application in the epidemiological study of hepatitis A.

We used IIF test for seroepidemiological study on 531 sera divided in age-groups obtained from apparently healthy subjects of Rome. Our results confirm the endemicity of HAV (Hepatitis A virus) infection in Rome with a prevalence of more than 50%. The application of the anti-HAV IIF (Indirect Immunofluorescence) test to a large number of sera demonstrated its usefulness as a quantitative and qualitative test in the epidemiological field.

Adolescent↗
PubMed1986

Recurrent herpes genitalis, severe impairment of specific cell-mediated immune response and bilateral femoral head necrosis: report of a case.

The case of a 56 years old patient, affected by recurrent herpes genitalis (RHG) is reported. The patient came to our observation on March 1983 and he was suffering from RHG for 20 years, before our study. Episodes of RHG were severe, due to local and general symptomatology. Characterization of immune response showed decrease of NK activity to the K562 cell line, impairment of specific cell mediated immunity to Herpes simplex virus (HSV) as well as a decrease of T cells with helper phenotype. HSV type 2 was stained from active lesions. Immunological alterations were present irrespective of phase of activity of the disease during all the follow up period (March 1983-March 1985). At the first visit the patient was found to be suffering from a femoral head necrosis (FHN) of the right leg. One year later the same disease appeared at the contralateral leg. The possible relationship between RHG, accompanied by the described immunodeficiency, and the FHN is described.

Femur Head↗